The present invention relates to the field of endotracheal tubes. More particularly, this invention deals with an apparatus and process for placing an endotracheal tube so that one or both lungs may be ventilated during an operation.
It is a common practice to provide human medical patients with artificial ventilation during surgery or in emergency situations. For example, accident victims will frequently require CPR or intubation by a paramedic in an emergency vehicle or by an anesthesiologist in an operating room. There are other surgical procedures which require use of an endotracheal tube to collapse one lung. For example, taking a biopsy from the lung to gather information on an infection, repairing a lobar defect due to infant emphysema, removing tumors, repairing an abscess or doing an esophageal triage. Generally, an endotracheal tube for collapsing one lung requires two separate passages, or xe2x80x9clumensxe2x80x9d.
Intubation is accomplished by insertion of an endotracheal tube through the patient""s mouth or nasal passages into the airway passage. Such devices have generally comprised a relatively pliable tube with means for connecting it to a respirator or other air supply mechanism for introduction of air into the lungs. An improvement to endotracheal tubes includes an inflatable/deflatable bag-like structure or balloon xe2x80x9ccuffxe2x80x9d around the exterior of the tube. The balloon cuff is conventionally located in a position along the endotracheal tube to engage the inner wall of the pharynx, larynx, or trachea depending upon the specific endotracheal tube design. When the tube is in place, the cuff is inflated and forms an air tight seal between the tube and the surrounding body tissue to prevent the escape of air pumped from the respirator into the lungs.
Both single lumen and double lumen endotracheal tubes are known. Typically, a single lumen endotracheal tube is an elongated tube that extends into the trachea of a patient upon intubation and includes one inflatable balloon cuff near its distal end. Commonly, the double lumen endotracheal tube is referred to as an endobronchial tube and, in addition to one lumen which extends to the trachea, has a second longer lumen which extends into the bronchus of a patient upon intubation. Typically, the double lumen endotracheal tube or endobronchial tube includes two inflatable balloon cuffs. The so-called double lumen endobronchial tubes, such as the well known xe2x80x9cCarlensxe2x80x9d and xe2x80x9cRobertshawxe2x80x9d tubes, allow for independent control of each lung through the separate lumina. One bronchus may be blocked by occluding one of the lumina at a position external to the patient, in order to isolate a particular lung.
The balloon cuffs are thin walled, high volume, and low pressure chambers or vessels which are designed not to compromise the blood flow in the tracheal or bronchial wall when inflated. Balloon cuffs are inflated by detachable syringes that are connected to smaller lumina or channels at the proximal end of the endotracheal tube. The seals formed by the inflated cuffs preclude the air that has been forced into the patient""s lungs from escaping through the trachea or bronchus. Additionally, the seals formed by the inflated cuffs provide a barrier to the flow of blood, mucus, and secretions.
The so-called double lumen endobronchial tubes also offer anesthesiologists the ability to insufflate selectively either the right or left lung or both lungs as required. The so-called double lumen endobronchial tubes also offer the physician the ability to collapse either lung as needed for certain procedures. The size of endotracheal tubes and endobronchial tubes is limited. In order to minimize damage to the tissue on the tracheal wall, the overall outer diameter of both single and double lumen endobronchial tubes is limited to approximately 1.2 cm. For this reason, the inner diameter of each lumen of a double lumen endobronchial tube is by necessity smaller than the inner diameter of a single lumen endotracheal tube. As a result, the inner diameter of the single lumen endotracheal tube can typically be no more than about 7.5 mm; whereas, the inner diameter of each lumen in a double lumen endobronchial tube is limited to a maximum of approximately 3.5 mm.
When an endotracheal tube is needed for pediatric use, the size limitations are even more restrictive. In pediatric patients, the size of the trachea is approximately the same size as the patient""s pinky finger. The size limitations virtually eliminate double lumen endotracheal tubes for infants since one or both of the lumens must have such a small diameter that the volumes of air or other gas that can be moved through the small lumen are less than that required by the patient. As a result, a single lumen endotracheal tube is required for procedures involving infant or toddler pediatric patients.
In pediatric patients, a single lumen endotracheal tube is advanced into the bronchus until breath sounds on the operative lung disappear. A fiberoptic bronchoscope may be passed along the endotracheal tube to confirm or guide placement of the endotracheal tube. There may be problems with such a procedure. The problems include incomplete collapse of the operated lung or failure to prevent contamination of the healthy, ventilated lung. Other techniques include use of two single lumen endotracheal tubes (one to each lung), use of a bronchial blocker to seal the lung and cause it to collapse. Use of a bronchial blocker generally requires more time than the previous method.
The larger lumen provided in a single lumen endotracheal tube affords the anesthesiologist access for other instrumentation through the lumen as required. The removal of mucus, the injection of medication, or the insertion of fiberoptic instrumentation for viewing within the endotracheal tube are examples of the additional instrumentation capability which is afforded by a single lumen tube. The ability to insert fiberoptic instrumentation through the tube significantly aids the anesthesiologist during intubation to accurately determine if the endobronchial tube is correctly positioned within the trachea and bronchus of the patient. These capabilities are restricted, if not prohibited, in the double lumen endobronchial tubes which by necessity have more narrow inner diameter passages and afford less access through the tubes by the anesthesiologist for the probes and instrumentation described.
For these and other reasons both prior art single and double lumen tubes are not fully satisfactory. There is a need for an endotracheal tube that can be inserted and quickly located in the correct position. There is also a need for an endotracheal tube that can be used to collapse one lung while ventilating the other lung. There is also a need for a single lumen endotracheal tube that can be used in pediatric patients. There is also a need for catheters that can be sealed at their distal ends.
The present invention is directed to an endotracheal tube which can be inserted through the mouth or nose and past the larynx of a patient and into the tracheal and mainstem bronchial passages. Extending from the tracheal portion of the tube is a bronchial portion which may be placed in either the left or right mainstem bronchus (singular) of the patient. The bronchial portion is angled with respect to the tracheal portion. The size of the angle corresponds to the angle between the trachea and the mainstream bronchus of the patient. Generally, these angles are age dependent and are known. The single lumen of the endobronchial tube of the present invention has an inner diameter sufficient to allow access through the single lumen to the patient""s lungs and respiratory system with additional instrumentation, as required. The bronchial portion of the endotracheal tube has a balloon situated on the inside of the tube which can be inflated or deflated. By inflating the balloon, the lung into which the bronchial portion has been advanced can be collapsed so that selected surgical procedures may be performed on the collapsed lung.
Positioned along the tracheal portion of the endobronchial tube of the present invention is at least one external balloon cuff which can be selectively inflated and deflated. When inflated, the tracheal balloon cuffs prevent retrograde air from escaping between the endotracheal tube and the trachea. Positioned between the external tracheal balloon cuff and the distal end of the endotracheal tube is an air outlet port from the tube through which oxygen from a respirator input to the endobronchial tube can escape into the patient""s respiratory system in order to ventilate at least one of the lungs. In one embodiment of the invention, the opening includes an extendable tube which can be inflated to extend it into the bronchus of the patient.
Located at a distal end of the bronchial portion of the endobronchial tube is a second air outlet port through which air may exit to allow successful collapse of the lung. Thus this acts as a vent. The internal bronchial balloon serves to provide a seal so that the collapsed lung is not ventilated when the tracheal portion is actively ventilated. The second air outlet may also be used to provide oxygen at low flows when deemed necessary clinically.
An endotracheal tube has a proximal end and a distal end and includes a tracheal portion having an opening at the proximal end and a bronchial portion attached at an angle to the tracheal portion. The bronchial portion has an opening at the distal end of the endotracheal tube. A balloon is positioned within the endotracheal tube. The balloon blocks the flow of gas through the bronchial portion of the endotracheal tube when inflated. The endotracheal tube also has an opening positioned between the proximal end and the balloon. The opening in the endotracheal tube between the proximal end and the balloon is positioned to allow ventilation of the lung opposite the lung into which the bronchial portion is adapted to extend into. The endotracheal tube further includes an inflatable bronchial extension tube having a first end and second end. One of the first end and the second end corresponds to the opening in the endotracheal tube positioned between the proximal end and the balloon and the other of the first end and the second end adapted to extend into a bronchus of a patient when inflated. In some embodiments, the endotracheal tube also includes a cuff positioned around the end of the bronchial extension tube adapted to extend into a bronchus of a patient when inflated. The cuff is separately inflatable from the inflatable bronchial extension tube. In other embodiments, the balloon positioned within the end of the bronchial extension tube is adapted to extend into a bronchus of a patient when inflated. The balloon is separately inflatable from the inflatable bronchial extension tube. The inflatable bronchial extension tube may include a bellows. The inflatable bronchial extension tube may also be adapted to extend at a selected angle from the tracheal portion of the endotracheal tube.
In some embodiments, the endotracheal tube may include a carinal seating mechanism which may be located near the junction between the tracheal portion and the bronchial portion of the endotracheal tube. The carinal seating mechanism is made of foam rubber. The carinal seating mechanism extends beyond the outer periphery of the endotracheal tube at a distance such that it does not interfere with passing the endotracheal tube through the trachea of a patient yet is at a distance adapted to seat against the carina of a patient. In some embodiments, the endotracheal tube includes an external inflatable cuff positioned on the tracheal portion of the endotracheal tube. In other embodiments, the endotracheal tube includes a first external inflatable cuff positioned on the tracheal portion of the endotracheal tube, and a second external inflatable cuff positioned on the bronchial portion of the endotracheal tube. The endotracheal tube further includes one or more channels having a distal end and a proximal end. The distal end of the channel is attached to an inflatable portion of the endotracheal tube and the proximal end of the one or more channels is positioned near the proximal end of the endotracheal tube. The angle between the bronchial portion and the tracheal portion of the endotracheal tube varies based on the age of the patient.
A method of inserting an endotracheal tube having a tracheal portion, a bronchial portion attached at an angle to the tracheal portion, and a carinal seating mechanism includes inserting the endotracheal tube through the trachea until the carinal seating mechanism is positioned at or near the site of the carina of a patient. The method may include guiding the endotracheal tube to a position where the carinal seating mechanism is positioned near the site of the carina of a patient using a fiberoptic device, or verifying that the carinal seating mechanism of the endotracheal tube is positioned near the site of the carina of a patient using a fiberoptic device.
Another embodiment of the endotracheal tube includes a tracheal portion having an opening at the proximal end of the endotracheal tube, a first bronchial portion attached at an angle to the tracheal portion and having a first open distal end, a second bronchial portion attached at an angle to the tracheal portion and having a second open distal end, and at least one balloon positioned within the endotracheal tube. The balloon blocks the flow of a gas through one of the first and second bronchial portions of the endotracheal tube when inflated. In some embodiments, the endotracheal tube may include an external inflatable cuff positioned on the tracheal portion of the endotracheal tube. In other embodiments, the endotracheal tube includes a first external inflatable cuff positioned on the tracheal portion of the endotracheal tube, and a second external inflatable cuff positioned on one of the first or second bronchial portions of the endotracheal tube. In still other embodiments, a third external inflatable cuff is positioned on the second bronchial portion of the endotracheal tube. The angle between the first bronchial portion and the tracheal portion of the endotracheal tube varies based on the age of the patient. The angle between the second bronchial portion and the tracheal portion of the endotracheal tube varies based on the age of the patient. At least one balloon is positioned within one of the first or the second bronchial portions of the endotracheal tube. In other embodiments, a second balloon is positioned within the other of the first or the second bronchial portions of the endotracheal tube. Each balloon is independently inflatable. The endotracheal tube may include a stylus. The endotracheal tube is adapted to receive the stylus through the tracheal portion and at least one of the first or second bronchial portions. In yet another embodiment, the endotracheal tube further includes at least one external cuff positioned on the tracheal portion of the endotracheal tube.
A method of inserting an endotracheal tube having a tracheal portion, a first bronchial portion attached at an angle to the tracheal portion, and a second bronchial portion attached at an angle to the tracheal portion, includes inserting a stylus into the endotracheal tube. The stylus passes through the tracheal portion and into one of the first or the second bronchial portions of the endotracheal tube. The endotracheal tube and stylus are inserted through the trachea and into a desired bronchus of the patient. The stylus is then removed. In one embodiment, the method further includes using a fiberoptic device to guide the endotracheal tube to a position where one of the first bronchial portion or the second bronchial portion is positioned in the selected bronchus of the patient. In another embodiment, the fiberoptic device is used to verify that the endotracheal tube is positioned such that one of the first bronchial portion or the second bronchial portion is positioned in the selected bronchus of the patient. The fiberoptic device may also be used to verify that both the first bronchial portion and the second bronchial portion are positioned in the selected bronchi of the patient.
Advantageously, the preferred embodiments of the endotracheal tubes described can be inserted and quickly located in the correct position while minimizing trauma to the various portions of the patient. The time required to perform this procedure is also minimized which saves a surgeon time in the operating room and also minimizes the amount of time the patient is under anesthesia. The endotracheal tubes can be used to collapse one lung while ventilating the other lung. The endotracheal tubes also have a single lumen and can be used in all types of patients, especially pediatric patients where double lumen endotracheal tubes cannot provide the necessary air flow through two smaller lumens. There is also a need for catheters that can be sealed at their distal ends. The endotracheal tubes described allow ventilation of either one or both lungs in infants and small children. A left or right endotracheal tube may be used allowing occlusion of one lung. The non-ventilated lung will allow for better surgical access either to the lung itself or to structures surrounding the lung. In addition, the device should accommodate the larger trachea and bronchial airway of older children, young adults, as well as all adults. The design is simple and incorporates a single lumen tube capable of isolating each lung by an internal cuff or balloon. The single lumen favors ease of placement.
The endotracheal tube described also enhances procedures requiring anesthesia during thoracic surgery in infants and children: for example, surgery on the lung for tumors, abscesses, or other lung abnormalities; or around the lung, e.g., esophageal stricture or tumor. The device is particularly effective in preventing trans-bronchial spread of blood and infectious secretions during surgery, while providing improved surgical access to the affected lung when one lung ventilation is deemed necessary. The endotracheal tube may also be useful in the pediatric intensive care unit, when severely asymmetric pulmonary disease exists.
The use of the described endotracheal tube will eliminate the surgeon""s and anesthesiologist""s need to use a variety of more cumbersome techniques, with tubes and bronchoscopes and will increase the availability of one-lung ventilation during anesthesia and surgery or ICU management of pediatric patients.